Actually you pay for the ads. There are no companies who "can afford to pay for the ads". Everything they spend on ads is directly included in the price of the product. If you aren't a customer then another customer paid to show you ads. Ads are not for the user they are to maximize profit. It's a trade off for a company they can spend some of the revenue on ads to generate more revenue thus making less profit per item but more overall. They target the optimum which means that several percent of revenue is put in ads. For everyone else this has only negative effects like less competition because the large player dominate trough ads or more resource wasting because ads make people buy stuff they don't need.